. "civil engineer and inventor" . "Ambursen, Nils F."@en . . "Nils F. Ambursen (February 6, 1876 \u2013 January 1958) was a Norwegian-American civil engineer and inventor, known for his influential dam designs in the early-20th century."@en . . "1958Z"^^ . "1876Z"^^ . . "1876-02-06Z"^^ . .